Hybrid electric device

ABSTRACT

A device includes a housing configured with a working element. The device further includes a motor configured for urging motion of the working element. The device further includes a power control module. The power control module is configurable for being in electrical connection with at least one of the motor, a first power source configuration and a second power source configuration. The first power source configuration is configurable for being electrically connected to a battery assembly having a DC power output. The second power source configuration is configurable for being electrically connected to a power inverter, the power inverter configured for receiving an AC power and further configured for outputting a DC power to the second power source configuration. The motor receives power via the power control module from the first power source configuration and/or the second power source configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part application and claimspriority under 35 U.S.C. § 120 to U.S. patent application Ser. No.11/899,616 entitled: Hybrid Electric Lawnmower filed Sep. 5, 2007,(pending) which is a continuation-in-part application claiming priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/670,932entitled: Hybrid Electric Lawnmower filed Feb. 2, 2007, (pending) whichis a continuation-in-part application claiming priority under 35 U.S.C.§ 120 to U.S. patent application Ser. No. 11/550,476 entitled: HybridElectric Lawnmower Having Dual Power Supply filed Oct. 18, 2006,(pending) which is a continuation-in-part application claiming priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/550,104entitled: Hybrid Electric Lawnmower filed Oct. 17, 2006 (pending). U.S.patent application Ser. Nos. 11/899,616, 11/670,932, 11/550,476 and11/550,104 are hereby incorporated by reference in their entiretiesherein. Further, U.S. patent application entitled Hybrid Electric Devicefiled Oct. 1, 2007 and having Express Mail Mailing Label Number EM005738901 US is also hereby incorporated by reference its entiretyherein.

FIELD OF THE INVENTION

The present invention generally relates to the field of hybrid electricdevices, and more particularly to a hybrid electric device having aboost/conserve power feature and a dual mode power supply for providingpower to an electric motor.

BACKGROUND OF THE INVENTION

Power tools are frequently utilized for lawn and property maintenanceoperations in and around various properties. The tools may be commonlyutilized for operations that require a motor, such as operationsrequiring the rotational actuation of a working element, such as acutting blade and/or an impeller. One such power tool is a lawnmower.Another such tool is a snow blower. Lawnmowers typically utilize arotating cutting blade, while snow blowers typically utilize a rotatingimpeller/fan. Some power tools may be operated from AC mains, such aspower supplied by a utility company or from an AC generator. Other powertools may be operated utilizing a battery.

SUMMARY OF THE INVENTION

Accordingly, an embodiment of the present invention is directed to adevice including: a housing configured with a working element; a motorconfigured for urging motion of the working element; a power controlmodule, the power control module configurable for being in electricalconnection with at least one of the motor, a first power sourceconfiguration and a second power source configuration, the first powersource configuration configurable for being electrically connected to abattery assembly having a Direct Current (DC) power output, the secondpower source configuration configurable for being electrically connectedto a power inverter, the power inverter configured for receiving anAlternating Current (AC) power and further configured for outputting aDC power to the second power source configuration, wherein the motorreceives power via the power control module from at least one of thefirst power source configuration and the second power sourceconfiguration.

An additional embodiment of the present invention is directed to adevice, including: a housing configured with a working element; a motorconfigured for urging motion of the working element; a power controlmodule, the power control module configurable for being in electricalconnection with at least one of the motor, a first power sourceconfiguration and a second power source configuration, the first powersource configuration configurable for being electrically connected to abattery assembly having a DC power output, the second power sourceconfiguration configurable for being electrically connected to a powerinverter, the power inverter configured for receiving an AC power andfurther configured for outputting a DC power to the second power sourceconfiguration, wherein the motor receives power via the power controlmodule from at least one of the first power source configuration and thesecond power source configuration, wherein the power control modulefurther includes a boost conserve switch including a conserve mode forsupplying a first voltage to the motor when the boost conserve switch isestablished in the conserve mode and a boost mode for supplying a secondvoltage to the motor when the boost conserve switch is established inthe boost mode, the first voltage being less than the second voltage.

A further embodiment of the present invention is directed to a device,including: a housing configured with a first working element and asecond working element; a first motor configured for urging motion ofthe first working element; a second motor configured for urging motionof the second working element; a power control module configurable forbeing in electrical connection with at least one of the first motor, thesecond motor, a first power source configuration and second power sourceconfiguration, the first power source configuration configurable forbeing electrically connected to a battery assembly having a DC poweroutput, the second power source configuration configurable for beingelectrically connected to a power inverter, the power inverterconfigured for receiving an AC power and further configured foroutputting a DC power to the second power source configuration, whereinthe first motor and the second motor are configured for receiving powervia the power control module from at least one of the first power sourceconfiguration and the second power source configuration.

A further embodiment of the present invention is directed to a device,including: a housing configured with a working element; a motorconfigured for urging motion of the working element; a power controlmodule, the power control module configurable for being in electricalconnection with at least one of the motor, a first power sourceconfiguration and a second power source configuration, the first powersource configuration configurable for being electrically connected to abattery assembly having a Direct Current (DC) power output, the secondpower source configuration configurable for being electrically connectedto a power inverter, the power inverter configured for receiving anAlternating Current (AC) power and further configured for outputting aDC power to the second power source configuration; and a switch forselecting between a first mode for charging the battery assembly whenthe power control module is receiving AC power and a second mode for notcharging the battery, wherein the motor receives power via the powercontrol module from at least one of the first power source configurationand the second power source configuration.

A further embodiment of the present invention is directed to a device,including: a housing configured with a working element; a motorconfigured for urging motion of the working element; the motor mountedon a deck having a first rigidity; and a reinforcing framework having asecond rigidity mounted to the deck.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not necessarily restrictive of the invention as claimed. Theaccompanying drawings, which are incorporated in and constitute a partof the specification, illustrate an embodiment of the invention andtogether with the general description, serve to explain the principlesof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The numerous advantages of the present invention may be betterunderstood by those skilled in the art by reference to the accompanyingfigures in which:

FIG. 1 is an isometric view of a hybrid mower;

FIG. 2 is another isometric view of the hybrid mower illustrated in FIG.1;

FIG. 3 is a perspective view of the hybrid mower illustrated in FIG. 1;

FIG. 4 is another perspective view of the hybrid mower illustrated inFIG. 1;

FIG. 5 is a side elevation view of the hybrid mower illustrated in FIG.1;

FIG. 6 is a rear elevation view of the hybrid mower illustrated in FIG.1;

FIG. 7A is a top plan view of the hybrid mower illustrated in FIG. 1;

FIG. 7B is a bottom view of the hybrid mower illustrated in FIG. 1;

FIG. 8 is a perspective view of the hybrid mower illustrated in FIG. 1;

FIG. 9 is a partial cross-sectional side elevation view of the hybridmower illustrated in FIG. 1;

FIG. 10 is an isometric view of the hybrid mower illustrated in FIG. 1,wherein the hybrid mower is operated via a battery;

FIG. 11 is an isometric view of the hybrid mower illustrated in FIG. 1,wherein the hybrid mower is operated via AC current;

FIG. 12 is an exploded isometric view of the hybrid mower illustrated inFIG. 1;

FIG. 13 is an exploded isometric view illustrating a removable batteryand a housing cover for the hybrid mower illustrated in FIG. 1;

FIG. 14 is an exploded isometric view illustrating a control unit forthe hybrid mower illustrated in FIG. 1;

FIG. 15 is an exploded isometric view illustrating a deck assembly forthe hybrid mower illustrated in FIG. 1;

FIG. 16 is an isometric view illustrating a height adjustment assemblyfor the hybrid mower illustrated in FIG. 1;

FIG. 17 is side elevation view of the height adjustment assemblyillustrated in FIG. 16;

FIG. 18 is an isometric view illustrating a hybrid mower, wherein thehybrid mower includes a cord holder;

FIG. 19 is an isometric view illustrating a hybrid mower, wherein thehybrid mower includes another cord holder;

FIG. 20 is an isometric view illustrating a hybrid mower in a stowageposition;

FIG. 21 is an exploded isometric view illustrating the hybrid mowershown in FIG. 20, wherein the hybrid mower is shown in a shippingconfiguration;

FIG. 22 is an isometric view of the hybrid mower illustrated in FIG. 1;

FIG. 23 is a circuit diagram of one option of a battery assembly for usewith the hybrid mower illustrated in FIG. 1;

FIG. 24 is a circuit diagram of one option of a power control circuitfor use with the hybrid mower illustrated in FIG. 1;

FIG. 25 is a circuit diagram of one option of the power inverter andhybrid control illustrated in FIG. 24 for use with the hybrid mowerillustrated in FIG. 1;

FIG. 26 is a circuit diagram illustrating one option of the powercontrol circuit for use with the hybrid mower illustrated in FIG. 1;

FIG. 27 is a circuit diagram illustrating an alternative option of thepower control circuit for use with the hybrid mower illustrated in FIG.1;

FIG. 28 is a circuit diagram illustrating still an alternative option ofthe power control circuit for use with the hybrid mower illustrated inFIG. 1;

FIG. 29A is a top plan view of a hybrid mower including two motors andtwo cutting blades;

FIG. 29B is a bottom view of the hybrid mower illustrated in FIG. 29 A;

FIG. 30 is a circuit diagram illustrating one option of the powercontrol circuit for use with the hybrid mower illustrated in FIGS. 29Aand 29B;

FIG. 31 is a circuit diagram illustrating an alternative option of thepower control circuit for use with the hybrid mower illustrated in FIGS.29A and 29B;

FIG. 32 is a cross-sectional side view of a motor assembly;

FIG. 33 is a circuit diagram illustrating a parallel configurationutilized by the motor illustrated in FIG. 32;

FIG. 34 is a circuit diagram illustrating a parallel configurationutilized by the motor illustrated in FIG. 32;

FIG. 35 is a circuit diagram illustrating one option of the powercontrol circuit for use with the hybrid mower utilized the motorillustrated in FIG. 32;

FIG. 36A is a partial isometric view illustrating a hybrid mower,wherein a battery compartment is in a closed configuration;

FIG. 36B is a partial isometric view of the hybrid mower illustrated inFIG. 36A, wherein the battery compartment is in an open configuration;

FIG. 37 is a top plan view of a power selection switch;

FIG. 38 is a partial cross-sectional side elevation view of a hybridmower, wherein an airflow path is illustrated;

FIG. 39 is a partial isometric view of a hybrid mower illustrating alever for a height adjustment assembly;

FIG. 40 is a circuit diagram of another option for the power inverterand hybrid control illustrated in FIG. 24 for use with the hybrid mowerillustrated in FIG. 1;

FIG. 41 is an isometric view of a hybrid snow blower; and

FIG. 42 is graphical depiction which depicts a relationship betweenmower load, voltage level, power consumption and blade speed inaccordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the presently preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

A hybrid electric device is described herein and set forth in the claimsand is partially depicted in the perspective view of FIG. 1 wherein anexemplary embodiment of a hybrid mower 10 is shown. The hybrid mower 10includes a deck 50 with an outwardly extending handle including an upperhandle 55 a and a lower handle 55 b. Positioned on top of the deck 50 isa control box 24 including a controller and at least one power selectionswitch 21. The deck 50 further includes a number of features including,but not limited to, the power control and supply described herein aswell as a DC motor, a cutting component housing including at least oneblade (cutting component), and other necessary features for making theelectric lawnmower described herein operable to function as desired.Such function and structure includes the DC motor for driving the blade,the DC motor being powered by alternative power supplies (power sourceconfigurations) which may include 120 VAC line voltage or DC powersupply such as a battery assembly 52. The motor drives the blade, whilethe power control system/power supply system of the hybrid electricmower allows the user to select the power source whether it be AC powersupply or DC power supply. In either selection, the power control systemof the electric mower provides adequate voltage to the motor. Further, aselection is available for the user of the present embodiment to drivethe motor in either conserve or boost mode. Conserve mode utilizes lesspower from the power source than boost mode, thereby increasing run timefor each full battery charge under such selection, should the DCoperation mode be selected. It is understood that conserve and boostmode may also be operable in AC operation mode.

Further, the motor may be designed as a dual voltage motor which has thecapability to operate on two different DC voltages, such as a motor asdescribed in U.S. Pat. No. 6,172,437. In one embodiment, the dualvoltage motor utilizes two separate commutators on a single armature.Each commutator connects to one set of windings (coils) that areseparated from the other. Each commutator is also in electric contactwith a corresponding set of brushes. The two sets of brushes may beselectively configured through the use of a user selection switch whichreconfigures the two sets of coils on the motor from seriesconnectivity, for higher voltage source such as rectified line voltage,to parallel connectivity, for a lower voltage source such as a batterypack.

In this dual voltage motor configuration, if the higher voltage isapproximately twice the potential of the lower voltage, the power supplywill provide substantially the same voltage potential across a first anda second commutator on the electric motor. For example if the mower isconnected to a standard AC power source of 120 VAC, a rectifier mayrectify the voltage to about 120 VDC (a higher voltage source). In suchcase, a series configuration will provide each set of coils about 60VDC. Alternatively, the mower may be connected to a 60 VDC battery pack(a lower voltage source). In such case, a parallel configuration willprovide each set of coils about 60 VDC also. Substantially the samevoltage provided to the sets of coils in both higher and lower voltagesresults in substantially the same revolutions-per-minute orrounds-per-minute (RPM) of the motor. In this manner, the dual-voltagelawnmower may be capable of executing speed control over the motor andthe cutting blade without the utilization of an electronic controller.This may represent a significant cost benefit to a consumer. In onespecific embodiment, the lack of a controller may represent a costsavings of approximately ten percent. It will be appreciated that thenumber of windings in the motor may vary and/or the diameter of wiresincluding the windings may vary.

It is understood that alternative designs of the mower may be employedwithout departing from the scope and spirit of the present invention.For example, in one embodiment, the mower utilizes a second electricmotor in order to increase the cutting width of the electric lawn mowerwithout increasing the blade diameter. Moreover, it will be appreciatedthat in addition to permanent magnet DC motors, many other various typesof motors may be utilized with the present invention. These motors mayinclude, but are not limited to, a universal motor, a brushless DCmotor, a switched reluctance motor, a stepper motor, and/or an inductionmotor.

Referring generally to FIGS. 1 through 11. A hybrid mower with a boostconserve feature of the present embodiment is depicted. A plurality ofwheels support the deck 50 such that the hybrid mower 10 may roll, bepowered or be pushed over terrain required to be cut by the blade 51.The specific configuration of the hybrid mower 10 of the presentembodiment, as depicted in FIG. 1, is not necessarily limiting in thatthe many structures and switches which are depicted may be positioned onmultiple surfaces or in multiple positions on the hybrid mower 10 andthus, the particular location and limitation of the depictions andstructure set forth are considered to be merely exemplary.

The hybrid mower 10 of the present embodiment incorporates controls nearthe upper handle 55 a such that they may be readily accessible to theoperator of the mower 10. A circuit breaker 28 having a key 28 a isutilized to break the electrical connection to the motor 56, hencestopping the blade 51, should the key 28 a be removed from a fullyinserted position. Further, the circuit breaker 28 also serves as atheft-prevention device as the motor cannot be started without the key28 a. Also found located on the upper handle 55 a is a blade clutchhandle 31. The blade clutch handle 31 is utilized as an interlock handleswitch to engage and disengage the DC motor 56 from rotating the blade51. The blade clutch handle 31 must be operatively held in closerelationship to the upper handle 55 a in order to engage the DC motor 56and correspondingly the blade 51. The blade clutch handle 31, whenplaced and held in close relationship to the upper handle 55 a, engagesan interlock handle switch as will be described herein which may be adouble throw switch, and which operates to act as a user's dead manswitch in order to disengage the DC motor if released. Such features maybe desirable in order to discontinue rotation of the blade 51 uponrelease of a manually actuatable handle within a limited and shortperiod of time. Thus, the interlock handle switch as depicted herein isintegrated with the blade clutch handle 31 and acts to operativelydisengage the DC motor and also cause resistive breaking (hard dynamicbreak) of both the motor and the blade upon release of the handle 31.

The hybrid mower 10 of the present embodiment is designed to be operatedon either AC line voltage from an AC power source (such as a wall plugor other AC source), or from a DC battery assembly (pack) 52 which ismounted on the deck 50 or in close conductive and operative relationshipwith the DC motor 56 depicted. The hybrid mower 10 of the presentembodiment is designed such that the operator may operatively selectfunctionality of the hybrid mower 10 and the motor 56 by either AC or DCpower. When the mower 10 is connected to an AC power source, as depictedin FIG. 8, an AC cord 22 is electrically connected to an AC receptacle23 positioned on the mower 10. The AC cord may be directly plugged intoAC line voltage which is typically 60 Hz 120 Volts. A battery pack 52located on the deck 50 may provide DC power to the motor 56. The batterypack 52 may be rechargeable.

Positioned on the mower 10 is also a power selection switch 21, asdepicted in FIG. 37. In one specific embodiment, the power selectionswitch 21 includes a battery charge indicator 83, a plurality of powersource selections 85, and a knob 86 for selecting a specific power mode.In the present embodiment, the power source selections 85 include acharge mode, a battery mode, a battery boost mode, a 120V cord mode anda 120V boost mode. The battery mode and the 120V cord mode are conservemodes, while the battery boost mode and the 120V boost mode are boostmodes. The boost modes provide the functionality of increasing thevoltage provided to the DC motor 56 thereby increasing the rotationalspeed of the blade 51 compared to conserve modes. When a boost mode isselected, a boost conserve switch in the controller is turned on.Conversely, when a conserve mode is selected, the boost conserve switchin the controller is turned off. Selecting boost or conserve mode mayincrease or decrease the voltage and thereby increase or decrease theactual drain on the battery pack 52 or other power supply due to theincreased current provided to the DC motor 56. It is understood that thepower selection switch may have different configuration. For example aplurality of buttons may be utilized in place of a knob. Further, adifferent set of power source selections may be provided.

In a present embodiment, the hybrid control system of the hybrid mower10 allows for the hybrid mower 10 to be powered from regular householdAC line voltage or from a DC voltage battery pack. The battery pack maybe designed to have a lower available operating voltage than the averagepeak voltage of household current. This arrangement may be provided inorder to allow the mower to run in a possible conservation mode in orderto preserve battery run time under less demanding grass conditions.Alternatively, when the mower is plugged in to AC household current orline voltage or when additional voltage is tapped from the battery packor from a battery associated with the battery pack, the hybrid mower 10of the present embodiment may selectively be operated in a boost orpower mode, the boost mode allowing for mulching of taller grass or pickup of various debris, such as pine cones, during operation.

Thus, for an example, when the hybrid mower 10 with power boost conservefeature of the present embodiment is in operation/being used for cuttingrelatively shorter grasses as shown in FIG. 10, since such task requiresless power, the battery mode (a conserve mode) may be selected by thepower selection switch 21. The battery pack 52 may be brought inelectrical conductivity with the DC motor 56 and the conserve settingmay reduce the rotational speed of the blade 51 thereby decreasing therate of drain of the battery pack 52 and also increasing the run andoperation time of the hybrid mower 10 per charge. However, should therebe a need to increase the rotational speed of the blade 51, the batteryboost mode may be selected to increase the voltage being supplied to themotor 56. It will be appreciated that the battery boost mode may supplyadded voltage to the motor from a secondary battery, and/or from anyother auxiliary power source included with and/or connected to thehybrid mower 10 as needed.

Alternatively, the hybrid mower 10 with power boost conserve feature ofthe present embodiment may be in operation while connected to an ACpower source, as shown in FIG. 11. Thus, for cutting relatively tallergrasses (as shown in FIG. 11), which requires more power, the 120V boostmode may be selected by the power selection switch 21. It will beappreciated that the 120V boost mode may supply added voltage to themotor from the battery pack 52, from a secondary battery, and/or fromany other auxiliary power source included with and/or connected to thehybrid mower 10 as needed. However, should there be a need to decreasethe rotational speed of the blade 51 (for example when operating over anarea where the grasses are generally shorter), the 120V mode (a conservemode) may be selected to decrease the voltage being supplied to themotor 56 to conserve energy. Thus, the boost and conserve feature asshown and depicted in the examples may be integrated with either powerselection of the AC power input line or DC power input line to the DCmotor 56. Further descriptions and implementations of such examples willbe described hereinafter.

In exemplary embodiments, the controller may include a speed sensor forsensing a speed of the mower blade and adjusting the voltage supplied tothe motor to maintain the speed of the blade of a substantially constantlevel. A relationship 2000 between mower load, voltage level 2004, powerconsumption 2002 and blade speed 2008 for a specific embodiment isdepicted in FIG. 42. As the load of the mower increases (from IDLEtowards FULL), the voltage level 2004 (hence the power consumption 2002)also increases in order to maintain the blade speed 2008 of thesubstantially constant level 2006 (for example within 5% in thisspecific embodiment).

It may also be desirable in one of the present inventive embodiments, toprovide a battery pack 52 which is easily removable from the lawnmowerdeck 50. The hybrid mower 10 of the present embodiment may be usedwithout the battery pack so as to be more easily maneuverable in slopedareas due to the reduced weight of not having the battery pack 52installed. In one specific embodiment, the total weight of the mower 10with the battery assembly is between approximately 60 lbs toapproximately 70 lbs, while the battery assembly weighs approximately 20lbs. Therefore, removing the battery assembly may reduce a considerableamount of the weight. Additionally, the mower 10 of the presentinvention may make it easier to stow/store the mower and charge thebattery pack 52 separately or alternatively, may promote ease ofcharging the battery when the mower 10 is still in operation (i.e., whenAC power is available). It may also be desirable that a battery cover 52a, as shown in FIG. 36A at a closed position and in FIG. 36B at an openposition, be provided to cover the location of the battery pack 52. Inaddition, as illustrated in FIG. 22, the mower 10 with the battery packremoved may be stored outside the garage 306, hence saving space thatwould otherwise be used to store a mower.

The DC motor 56 may be a permanent magnet type DC motor and may bedesigned to receive power from the battery and/or from the hybrid powercontroller which will be described herein. The DC motor 56 may beprovided to power the rotating blade 51 while cutting vegetation and themotor 56 may act as a generator in order to provide resistive breakingafter deactivation of the interlock handle switch described therebyproviding a resistive load to stop the blade quickly once the bladeinterlock handle 31 is released. It is contemplated, as shown in FIG.38, that the motor 56 may be designed to further include a fan 91 topromote cooling of the DC motor 56, thereby providing air circulationvent paths 93 across the brushes and through the motor. For example, ina specific embodiment, the motor promotes airflow up (relative to theground upon which the mower is supported) and across the heat sink.Then, the airflow proceeds down through the motor (i.e., within themotor housing). Alternative embodiments with multiple motors or withmultiple commutators selectively operating in series or in parallel mayalso be provided.

As previously described, the blade 51 may be provided in order to mulchor cut vegetation. Typical blade tip speeds may be between approximately16,000 to 19,000 ft. per minute during non-cutting and betweenapproximately 12,000 to 18,000 ft. per minute during cutting ofvegetation with a proportionate horsepower rating for the DC motor ofabout 1.5. Higher speeds may be indicated/attained when operating fromAC line voltage while lower speeds may be recognized/attained whenoperating off of Battery DC voltage. Alternatively, in a low power orconservation mode, the run time may be considerably longer with batterylife expected to be increased by 50% and with the speed of the DC motor56 correspondingly decreasing to drive the blade 51 at approximately14,000 ft. per minute blade speed as measured at the tip of the blade.The various speeds of the blade 51 can correspond to a plurality ofvoltage outputs from the hybrid power supply as seen/detected/receivedby the DC motor 56. Namely, to provide higher speed functionality of theblade, a voltage of 66V or 72V DC may be presented to the DC motor witha 300 watt/hr batter charge capacity. Alternatively, in conservation orlow speed mode, which may thereby correspond to higher battery pack runtime duration or less current draw from the power supply, the powerconsumption may be significantly reduced by providing 60V or less to theDC motor 56. These various power consumption modes may be providedthrough the use of the boost and conserve switch which, as can be seenfrom the examples depicted herein, may be a single pole double throwswitch as shown in order to increase the voltage through the variousmeans depicted and described in the multiple examples hereof.

Thus, when the mower 10 is in conservative mode, the corresponding bladespeed may be less than 15,000 ft. per minute blade tip measurement andpreferably at 14,000 ft. per minute blade tip measurement or lessthereby significantly increasing the battery pack charge run time whenthe battery pack is in operation and the power selection switch 21 isselected/positioned in the battery mode. In such an instance, the 60volts may be provided to the DC motor by the battery pack 52, which mayinclude a series of five batteries connected in series, each of thebatteries providing 12 volts. Alternatively, should the power selectionswitch 21 be set to the battery boost mode, an additional or secondarybattery which may be integrated with or separated from the battery pack52, may be brought in series with the battery pack 52 power supplythereby increasing the voltage to 66 or 72 volts, depending ondesirability and the blade speed at which the mower 10 is to beoperated.

The battery assembly may include a stack of DC batteries connected inseries. In one specific embodiment, as shown in FIG. 23, the batteryassembly 700 includes a stack of five lead acid five amp-hour 12V DCbatteries 702. In this configuration the voltage of the battery assemblymay be around 60V. It will be appreciated that when fully charged, thevoltage of the battery assembly 700 may be approximately 66V and, duringbattery discharge, may be reduced to approximately 50V. Further, it willbe appreciated that as the battery discharges, the speed of the mowerblade may be reduced proportionally. For this reason, it is contemplatedthat the speed of the mower blade may be set based on the fully-chargedvoltage of the battery assembly and/or the battery assembly and one ormore other power sources, as utilized in a power boosting configuration.

In a further embodiment, the battery assembly 700 may be connected inseries with an auxiliary battery 54 in a power boosting configuration,through the control of the boost conserve switch 26. The auxiliarybattery 54 may be a five amp-hour 12V DC battery. In this configuration,when in the power boosting mode (boost conserve switch 26 is set to ON),the voltage of the battery assembly and the auxiliary battery togethermay be around 72V. It is understood that variations may be provided inthe configuration and implementation while running in DC mode for thebattery pack depicted herein as this example is provided merely fordescriptive purposes only and many other embodiments including bringingbatteries in parallel, series, or providing additional power sources maybe utilized.

While the example of the conserve and boost switch has been provided foroperation in DC mode, alternative embodiments which may provide anincrease in motor speed while running in AC mode will also be describedherein. Such embodiments may include increasing the step down voltagefrom the power supply controller as presented to the DC motor oralternatively bringing in series the secondary battery while alsooperating in AC mode thereby increasing the DC voltage presented to themotor and resulting in an increase in rotational speed of the blade.Thus alternative embodiments are shown and depicted wherein the powersupply of the present embodiment generates DC power to the motor andwherein the boost or increased voltage may be derived from either thepower supply by various techniques, such as depicted, or by providingadditional voltage from the battery pack or secondary battery, either ofwhich may result in increased operational speed of the motor and bladespeed.

One other aspect of the present embodiment of the hybrid mower 10 of thepresent embodiment is the ability to provide a user selectable powersupply to a DC motor driving the blade 51. In the hybrid mower 10 of thepresent embodiment, a DC motor 56 is provided to rotate blade 51 on themower deck 50 due to its energy use and supply characteristics. A userselectable alternative power supply or power selection switch 21 isprovided in order that the DC motor 56 may be user switchable from powersources, namely from an AC 120 volt 60 Hz power input representing linevoltage should an extension cord or line voltage be readily accessible,or alternatively, to a battery pack DC voltage provided on board of themower, both power supplies selectable by the operator and both powersupplies driving the same motor mounted on the lawnmower housing or deck50. Such an option may be highly desirable and unique in that the usermay selectively operate the mower from various user selectable inputsrepresenting alternative power inputs, a first power input beingprovided at the power selection switch 21 representing a power inputline from a battery pack 52, with a second power input being provided atthe power selection switch 21 representing the AC line 22.

Further, as an alternative design element, an automatic mode may beavailable for the power selection switch 21. Under the automatic mode,the power control circuit 60 could include a solid state relay which, asan example, has a zero crossing circuit for voltage detection toactivate a triac or other relay device to automatically connect theelectric motors to line voltage, when plugged into the power controlcircuit. Such user selectable power selection can thus be automated byan automated voltage or other detection circuit or may be actuated bythe switch 21 herein described. It is appreciated that the automaticselection may be overwritten by the user selection by setting the powerselection switch 21 to an alternative power source selection. Inexemplary embodiments, a switch/relay/solid-state switching device maybe utilized to accomplish power supply selection.

The controller may employ a set of algorithms to control the batteryassembly charge logic. For example, during an operation in AC powermode, the algorithm employed by the controller may examine the chargelevel of the battery assembly, and determine if recharging of thebattery assembly is necessary. In one embodiment, a PIC algorithm(s)programmed on to an ASIC programmable controller chip is utilized tocontrol all of the charge logic. It is further contemplated that thecontroller may contain a current sensor that senses the electric currentgoing to the motor 56 and examines/references/compares the current levelagainst the blade speed to provide a soft start ramp up. The currentsensor may also serve as a current overload protection device,preventing circuit breaker trip should a sudden drop of load occur(moving from a taller grass area to a shorter or no grass area).Further, the current sensor may signal a raise of the voltage to meet anincreased power demand, thus maintaining the blade speed at a relativelyconsistent level.

Referring to FIGS. 12 to 15, there is shown an exploded view of anexemplary embodiment of the mower 10. Enclosed between a housing cover82 and the deck 50 includes a controller (power control module) 20mounted on to a generally triangular shaped support plate (controlmount). Positioned on top of the controller is the power selectionswitch knob 86, covered by a control box cover 84. In one specificembodiment, the control mount is formed as an A-frame structure that isindependent of the housing cover 82. This configuration may aid in theassembly of the hybrid mower 10. The knob 86 is accessible by a userthrough an opening on the housing cover 82. Also mounted on to thesupport plate are additional circuit boards, electrical connectors, anAC receptacle 23, and cooling devices such as a heat sink and/or a fan.Attached to the bottom of the support plate on one end is the topportion of the motor 56, which is electrically connected to thecontroller 20, and has its bottom portion attached to the deck 50. Ashaft 57 is attached to the motor to transfer rotational energy to theblade 51, which is rotatably attached to the bottom of the deck 50, andconnected to the shaft 57 through an opening at the bottom of the deck50. Positioned on the bottom of the deck 50 are a rear axle 302supporting rear wheels, and a front axle 304 supporting front wheels.The front and rear axles 302 and 304 may comprise self-aligning, snap-inaxles (as an assembly aid and labor reducer).

As depicted in FIG. 15, the deck 50 is reinforced utilizing reinforcingribs 90 in combination with a steel reinforcing framework, which may beprovided by the lower handle 55 b or separate tube extending around theperiphery of the mower deck and intersecting with the handles and/orother structural components mounted to the mower deck. In one specificembodiment, a steel tube extending around the mower deck is connected tothe mower deck utilizing screws or other fasteners as required. In oneembodiment, the deck made of plastic with reinforcing framework is ableto achieve similar rigidity of a steel deck. It is understood that thedeck 50, the reinforcing ribs 90, and the lower handle 55 b may be madeof various materials. For example, in a specific embodiment, the deckand the reinforcing ribs are made of plastic. Alternatively, thereinforcing ribs may be made of steel or other metal materials.Additional suitable materials may include fiberglass and other compositematerials.

Also mounted on to the top of the deck 50 is the lower handle 55 b. Inone specific embodiment, the lower handle 55 b includes a generallyparallel portion, which is generally parallel to the deck on one end,and an outwardly extended portion on the opposite end. The outwardlyextended portion forms an angle with the deck 50. Thus, to securelysupport the outwardly extended portion of the lower handle 55 b, twohandle support posts (axle towers) 88 are positioned on either side ofthe deck 50 above the location of the rear axle 302. This setup allowsthe outwardly extended portion of the handle to establish a contactpoint with, and be secured onto, the support post 88. A generallytriangular shape formed by the handle, the deck and the post allows theattachment relationship between the lower handle 55 b and the deck 50 tobe more stable and less vulnerable to breakage and/or flexing. In onespecific embodiment, the axle towers 88, together with the motor 56 andthe controller 20 mounted on the deck 50, form a box structure which ismore stable and provides more protection to the motor 56 and thecontroller 20.

It will be appreciated that strengthening the rigidity of the mower deckmay be desirable for providing an added feel of quality for a consumer.It is understood that alternative designs of the handle may be employedwithout departing from the scope and spirit of the present invention.For example, in one embodiment, the handle may have the lower handleadjustably attached to an upper handle. Thus, the upper handle 55 a maybe folded down, as illustrated in FIGS. 21 and 22, requiring a smallerstorage and/or packaging space. Height adjustment of the handle may alsobe made available in this setup. Alternatively, the handle may bedesigned as one-piece having one end attached to the deck 50 and theopposite end to be handled/grasped by the user.

A single point height adjustment assembly is utilized in one specificembodiment. As illustrated in FIGS. 16 and 17, this single point heightadjustment assembly includes a lever connected to a first bar 302. Thefirst bar 302 is connected to a second bar 304, via a connecting rod.The connecting rod may be coupled to the height adjustment handle 72utilizing a spring 70. In exemplary embodiments, the first bar 302 andthe second bar 304 are offset from a rotational axis for a set of wheelsconnected to the lawnmower. In this manner, adjustment of the handle 80will cause the first and second bars 302 and 304 to move around fixedpoints and thereby raise/lower the wheels as illustrated in FIG. 17.This assembly may be applicable to electric, gas, and even push mowers.

It is understood that alternative designs of the mower may be employedwithout departing from the scope and spirit of the present invention.For example, in one embodiment, the power control switch 21 ispositioned near the controller 20 on the deck 50 to reduce the amount ofwiring needed for connection. In an alternative embodiment, the powercontrol switch 21 may be positioned near the circuit breaker 28 on theupper handle 55 a to promote ease of use. Further, an AC cord holdingdevice may be utilized to promote easier retrieving or retracting of theAC cord 22. In one embodiment, as illustrated in FIG. 18, an AC cordholding device 76 of a generally rectangular shape is rotatably attachedto the handle. Rotating the device 76 in one circular direction (forexample clockwise) may retract the AC cord 22, while rotating the device76 in a reverse circular direction (for example counterclockwise) mayallow user to retrieve more of the AC cord 22. Alternatively, the device76 may be configured in other geometrical shapes, for example, in agenerally circular shape, as depicted in FIG. 19. In still anotheralternative embodiment, the cord holding device includes two stationaryholders distanced apart from each other (for instance 1 foot apart),where the user may wind/unwind the AC cord around the two stationaryholders to retract/retrieve the cord 22.

Turning to an exemplary embodiment shown in FIG. 24 wherein a powercontrol circuit 60 is depicted providing, among other things, the boostand conserve power features of the present embodiment. The DC electricmotor 56 is shown in electrical connectivity with the various powercontrol circuit elements 60, 100 which include the interlock handleswitch 31, for example being a double pole double throw switch, acircuit breaker 28 being, as depicted herein, a 35 amp breaker, aboost/conserve switch 26, in this example being a single pole doublethrow switch, a power selection switch 21, in this example being asingle pole double throw switch, a battery pack 52 which is depicted asa 60 volt DC battery pack providing 60 volts presented to the motor 56when operatively selected by the power selection switch 21, and a hybridAC/DC controller 100 which serves as a power inverter or step downcontroller for converting the line voltage 120 VAC presented by the plug23. The battery pack is shown as sharing a common ground with otherportions of the power control circuit but may be in electricalconnectivity with the power control circuit in many known and understoodmanners without actual connected electrical wiring as long as the useroperation of the lawn mower is actuated through activation of thevarious switches.

In this present example, the boost selection switch 26 provides anincreased voltage to the motor 56 by virtue of modifying an inputresistive value or timing signal value to the pulse width modulationcontrol unit 120 (see FIG. 25), which will be described below, in orderto alter the gating of the IGBT thereby affecting the voltage wave format the output of the power inverter or step down controller 100. The inrush current limiter may be provided as shown in order to preventover-saturation of the circuit during the initial startup and energizingof the circuit. The rectifier 110 (see FIG. 25) as is commonlyunderstood rectifies the voltage from AC to DC, in this case utilizing afull bridge rectifier as shown. However, many different forms ofproviding a step down controller are known in the art and the depictionsset forth are not to be considered unduly limiting.

As depicted in FIG. 24, the design consists of the AC receptacle 23which connects to the hybrid AC/DC controller 100 acting as a voltageconverter which in turn is connected to a single pole double throw powerselection switch 21 and a single pole double throw boost switch 26. Theboost switch 26 is the boost conserve switch depicted and describedherein and it provides resistive loads to the CMOS micro-controller forpulse width modulation control 120 when selected and opens the contactswhen off. The power selection switch 21 toggles the DC motor between theoutput of the step down controller 100 and the DC battery voltage source52. The output of the power selection switch 21 feeds a voltage metershown which may be connected in parallel with the double pole doublethrow interlock handle switch 31, the interlock handle switch 31toggling between shorting the DC motor 56 through resister R1 to groundand connecting the output of the power selection switch 21 through acircuit breaker 28 to the DC motor 56.

In this embodiment as depicted in FIG. 24, the boost switch 26 mayprovide increased voltage to the motor 56 when the hybrid mower 10 ofthe present embodiment is plugged in and running off of line voltage ACpower. Such boost may be effectuated by modifying the pulse widthmodulation control 120 through alteration of the input resistive load atinput pin 7 of the micro-controller shown in FIG. 25. More descriptionof the power inverter and/or step down controller 100 of the powersupply and mower of the present invention will be set forth herein.

Turning to an additional embodiment for the power supply circuit 160 ofthe present embodiment in FIG. 26, this embodiment provides an AC wallplug 23 which connects to an AC voltage and to the hybrid AC/DCcontroller 100 which in turn is connected to the power selection switch21 which allows toggling between output of the AC/DC hybrid controller100 when in the AC selection and to a boost conserve switch 26 andalternative power source when in the DC position. The boost conserveswitch 26 toggles between shorting the positive side of the batterysource 52 directly to the boost switch 26 when off and connecting thebattery source 52 in series with the secondary or boost battery 64before connecting to the power selection switch or AC/DC switch 21. Thepower selection switch 21 then feeds a voltage meter V which isconnected in parallel with an interlock handle switch 31, here depictedas a double pole double throw switch. The interlock handle switch 31toggles between shorting the DC motor 56 through a resistor R1 to groundand connecting the output of the power selection switch 21 through thecircuit breaker 28 to the DC motor 56.

As depicted, in the example shown in FIG. 26, additional voltage isprovided to the DC motor 56 when the hybrid mower is positioned in theDC power selection option and the boost switch 26 is activated therebyproviding an additional 6 volts DC to the 60 volts DC provided by thebattery 52. A secondary battery 64 provides additional voltage to themotor thereby increasing the motor speed and corresponding blade speedthrough actuation of the boost/conserve switch 26 to the boost setting.Thus, the power control circuit or power supply 160 depicted in FIG. 26allows the operator, while in the DC battery operation mode, to increasethe operating speed of the motor 56 corresponding to/via the additionalvoltage provided by the secondary battery 64. Controls are also providedallowing the operator to select between the operation of the motor 56through the use of line voltage, namely 120 VAC, or through the use ofthe battery pack 52. Depicted herein is a secondary boost battery 64which is provided separately from the battery pack 52, but it may bemore practical to provide a secondary boost battery 64 in combinationwith and contiguous to the battery pack 52 as assembled and shown in thefigures. Thus, the secondary boost battery 64 may be continuous with thebattery pack 52 or may be separate but is provided to add additionalvoltage to the motor 56 in order to modify the operating output voltageof the power supply as presented to the motor 56.

The hybrid AC/DC controller 100 as shown provides both power inverterand step down capabilities in order to modify and regulate the 120 VACto the proper voltage required to run the DC motor 56. However, thesefunctions are provided to be only exemplary. The controller 100 acts asan inverter via rectifier 110 and also acts to properly modulate thevoltage via the PWM controller 120 and associated gates. The powerinverter and step down controller 100 may be part of the power supply orpower control module 60 (see FIG. 24), 160 (see FIG. 26), 260 (see FIG.27) and 360 (see FIG. 28) as needed, or may be excluded, depending onthe voltage characteristics of the input line voltage and therequirements of the electric motor implemented in the present design.

An alternative construction for the power control is the power supplycircuit 260 depicted in FIG. 27 wherein both 120 VAC may be provided tosupply power to the motor 56 while optionally a 60 volt DC battery maybe provided and may be operatively selectable by the user through/viathe power selection switch 21 a. As depicted in this example, the boostswitch 26 a is operative to bring in series a secondary battery 64 whichis 6 volts DC (when set in “BOTH” mode) with the voltage provided by thehybrid controller 100 of the power supply or the battery pack 52. Thesecondary battery 54, as previously described and as depicted in thisembodiment of the power control circuit 260, may be in combination withthe battery pack or may be secondary and separate therefrom.Additionally, as shown in the illustrated example, the 6 volt battery isbrought into the circuit in series with the DC output of the hybridcontrol 100 or with the battery pack 52. Also, many variations for thestructure, assembly and actual value of the secondary battery 64 for allembodiments may be provided in order to increase the voltage to themotor 56.

As depicted in FIG. 27, the power selection switch 21 a further providesfor three settings allowing user selectable options of powering the DCmotor 56 by either 120 VAC, by the direct battery pack connection or bya hybrid BOTH connection. When operating in the strictly 120 VAC mode,the hybrid AC to DC control 100 of the present embodiment regulates andmodulates the voltage for proper supplying of voltage to the DC motor56. Alternatively, the power selection switch 21 a provides for a DCoperation whereby the motor 56 is operated merely by the battery pack52. A third option is placement of the power selection switch 21 a intothe BOTH mode, wherein there may be a limited amount of powercontribution from the battery. In such instance, voltage drops caused byincreased load on the motor 56 may result in increased contribution fromthe battery pack 52. Additionally, as depicted in the embodiment shown,the boost conserve switch 26 a may be provided for contribution ofadditional voltage from the secondary battery 64 when the powerselection switch 21 a is placed in either the BOTH or DC mode. In suchan instance, the secondary battery 64 is brought in series with thevoltage contribution from either the power supply 100 or the batterypack 52.

Turning to FIG. 28, an alternative construction and embodiment of thepower control and supply circuit 360 is depicted. In the exampledepicted, the power supply circuit 360 consist of a 120 VAC wallreceptacle 23 which connects to the hybrid AC controller 100 which inturn is connected to an exemplary single pole double throw boost switch26 thereby allowing the circuit to bypass boost battery 64 when off orbe connected to the boost battery 64 when on. Additionally, the circuitcontinues to an exemplary single pole double throw power selectionswitch 21 which toggles between the output of the speed selection switch26 when in the AC position and the DC battery assembly 52 when in the DCposition. The power selection switch 21 feeds a voltage meter V which isconnected in parallel with an exemplary double pole double throwinterlock handle 31, the interlock handle switch 31 toggling betweenshort in the DC motor 56 through a resistor R1 to ground and connectingthe output of the power selection switch 26 through a circuit breaker 66to the DC motor 56. In this example of the power control circuit 360,the boost or secondary battery 64 is brought in parallel with the powerpack 52 or with the output of the hybrid controller 100 which mayincrease the current capacity for the motor when in higher speed orboost mode.

Multiple variations of power control module or power supply may beprovided and are described herein. When mentioned herein as a hybridpower controller, power supply, power control module, step downcontroller or hybrid controller, these terms are collectively meant toimply providing electricity to the motor placed on the mower housing. Nosingle element set forth in the exemplary embodiments provided herein,namely the power supply elements of the switches, battery packs, circuitbreakers, inverters and modulation elements are to be unnecessarilyapplied to the interpretation of these terms. In fact, the power supplycircuit collectively described herein may be implemented through the useof a significant number of alternative structures for regulation,modulation, controlling or limiting the proper voltage or power to themotor implemented in the examples herein. No unnecessary limitationshould be interpreted from the particular use of the term controller,inverter, regulator or regulation or modulation as depicted herein.

Turning to the exemplary power inverter and in combination step downcontroller 100 which acts as a portion of the power control module, thehybrid controller 100 receives as input 120 volts AC which, in thisexample, is inverted utilizing a full bridge rectifier 110 depicted inFIG. 25. An in rush current limiter is provided also to prevent currentsurges during initial loading of the circuit and prevent further damageor over-saturation. A number of different inverter designs may be usedin order to provide voltage rectification. As depicted in the presentexample, a full bridge rectifier may be utilized but this may bereplaced with other known inverter circuitry as is available and knownin the art.

In addition, as depicted in FIG. 25, an optional boost switch may beprovided which may correspond to the boost switch 26 depicted in FIG.24. In the present exemplary embodiment, the optional boost switch maybe operable to modify the input to the pulse width modulation controller120 which defines the voltage output for the step down controller 100.As shown, a micro-controller is utilized in order to set the appropriatepulse rate for the PWM control and feeds into the insulated gatebi-polar transistor (IGBT) which provides the switching or pulse gatedriver 122 for the DC output of the hybrid AC/DC control 100. Thus, thehybrid controller 100 incorporates, but does not necessarily require,the utilization of voltage rectification and a voltage rectifier as isnecessary in combination with variations of voltage modification such asa pulse width modifier. However, multiple options for step down voltageand control are known and may be utilized such as diode controls, triaccontrols, MOSFET controls and the like. Many of these are well known inthe art and may be utilized in the step down controller and powerinverter in combination as described herein. Additionally, as depicted,the pulse width modulation control circuit 120 receives as input in onepossible embodiment the ability to modify the voltage by use of theboost switch. The boost switch in this embodiment modifies the referencesignal fed into pin 7 of the micro-controller for the reference valuewhich operates to modify the gating of the IGBT and therefore, thevoltage characteristics of the DC output depicted. The boost modedepicted provides the alternative function of a boost integrated withthe power inverter and step down controller. As shown integrated withthe controller 100 in FIG. 24, the boost switch can be alternativelyprovided in many connections and this integrated boost switch may beintegrated with many of the other alternative embodiments.

Referring now to FIG. 40, the hybrid mower 10 may include a switch forselectively activating a battery charge operation, such as a charge modeactive switch 124, or the like. The charge mode active switch 124 may beutilized for switching the hybrid mower 10 from a battery charging modeto a mode where the battery is not being charged, and then back again.In one specific embodiment, the battery is charged in the mower whilenot in operation, either by automatic switch or by user selectableswitch. In another specific embodiment, the battery may be charged whilein use (e.g., while mowing a lawn with the cord connected). In anembodiment with a user selectable switch and in situ charging, anoperator may be able to control when power from AC mains is beingutilized to charge the battery. Further, a battery charge light 126(e.g., a Light Emitting Diode (LED) or another type of light and/orindicator) may be provided to indicate when such charging is takingplace. It will be appreciated that the charge mode active switch 124 maybe placed on the hybrid mower 10 and indicated accordingly with variouslabels and/or indicia. Moreover, it will be appreciated that amulti-colored LED and/or multiple LEDs may be utilized to indicatevarious charging states to an operator, such as the battery chargingmode and modes in which the battery is not being charged. Further, itwill be appreciated that various battery charging level indicators maybe provided in a similar manner, including various combinations ofindicators (e.g., tones, flashing lights, multi-colored lights, meters,and the like). Additionally, it should be noted that battery chargeinformation may be presented by the battery itself (e.g., the batterymay include an indicator for demonstrating a charge level to a user ofthe hybrid mower 10).

As is known, many variations of a step down controller and inverter maybe utilized and in general, the power control module of the presentembodiment may utilize power input of 120 VAC and may incorporate manyswitches and controls for electrically connecting the DC motor to eitherthe 60 volt DC battery or the DC output of the hybrid power controller.This may include utilization of a power source switch as indicatedwherein the power source switch effectively has a first power input as aconnection of the power control module of the DC output of the powerinverter and step down controller 100 or receive as a second input the60 volt DC of the battery pack, the power selection switch providing theability of the operator to switch between 120 VAC power and 60 VDC powerfrom the battery pack. The power selection switch may be directlyconnected to the DC motor, in this exemplary embodiment a 60 volt DCmotor, which operates the blade. The 60 volt DC motor may beoperationally modified by utilization of a boost switch which isoptional in many embodiments depicted herein, the boost switch changingvoltage applied to the DC motor from 60 volts by an incremental value,thereby increasing rotational speed of the blade as necessary by theoperator. Such increase in blade speed, as previously indicated, may benecessitated by thicker grass or other items being cut/mulched by thehybrid mower 10 of the present embodiment. This boost/conserve functionwhich is shown herein provides the ability through the many embodimentsdisclosed to increase the voltage of the power control module, therebyincreasing the rotational speed of the blades. As indicated, this may bedesirable for short periods of time and may provide a first power outputof the power control module, the first power output higher than a secondpower output, the second power output being a conserve feature whereinthe DC motor draws less current and thereby increases the battery lifecharge of the battery pack. However, such feature does not have to beimplemented only with the use of DC operation and DC power input as itis apparent that the increase rotational speed (boost) feature may beimplemented also with 120 VAC wall power by increasing the DC voltageoutput of the hybrid AC/DC control 100 or by adding a supplemental DCpower supply from the operating batteries, whether primary or secondary.

Referring now to FIGS. 29 through 31, an alternative embodiment of theelectric lawnmower of the present invention is depicted. In such analternative construction, the electric lawnmower 500 has a first and asecond blade 551A and 551B mounted to a housing 550. Driving each of theblades, 551A and 551B are a first and second motor 552A and 552B asdepicted in FIGS. 30 and 31. The alternative dual motor construction asis depicted may substantially use similar power control circuitry withthe modification in the series or parallel connection of the DC motors552A and 552B to the power supply voltage. It may be desirable toprovide the DC motors with either 120 VAC line power (which is currentrectified) or with the battery pack supplied DC electrical power. In themultiple embodiments provided, two blades may be provided to cutvegetation within and below the deck 550 of the electric lawnmower 500.A total cutting width of approximately 19 inches may be provided whereineach of the blades may be about 9.5 inches (end-to-end length). Whenattempting to cut a relatively large diameter with a single blade, suchas the entire 19 inches of the housing width, excessive battery drainand power consumption may be experienced due to air movement resistanceencountered by the blade. The air movement load may goes upexponentially as related to the blade speed thus adding a significantlyhigher load in addition to the normal vegetation cutting resistanceload. The increased rotation speed of the blade and increased length ofthe blade may cause a significant proportion of the power supply to beused for moving air as opposed to cutting of vegetation.

Thus, for cutting of wider diameters, it may be preferable to utilizetwo motors and two blades working in tandem. By utilizing two motors asopposed to a single motor with an increased rotational speed,significant power savings may be experienced and run time lengths forthe power supply battery as well as power consumption in both DC and ACoperations may be significantly reduced. Additionally, when using dualmotors 552A and 552B, such dual motor implementation may preferably notbe used in series in conjunction with battery operation due to themotors running at half speed, i.e. sharing the battery pack suppliedvoltage in series. Thus, in a preferred implementation for dual motoruse, although not necessarily required, the DC electric motors maypreferably be placed in parallel (as is depicted in FIG. 30) in certainoperations, such as when operated by the battery pack, and possibly inseries in others, such as when connected to higher line voltage.However, the DC motors may be placed in either operation as is deemednecessary. Also, power usage may not become an issue when providing linevoltage through the hybrid AC to DC controller wherein the AC current isrectified for operation of the DC motors depicted.

As depicted in FIG. 30, the dual DC motors 552A and 552B for the powercontrol and supply system 520 of the present embodiment are shown inparallel. A circuit breaker may be provided in combination with theinterlock handle switch as previously described in order tooperationally connect and disconnect the motors as selected by the userthrough the blade clutch handle 31. Further, an AC/DC operational switchmay be provided for selection of either power supply, either AC linevoltage or DC battery power supply as previously described. Further, ahybrid AC/DC controller may be utilized to implement rectification ofthe 120 VAC to provide an adequate supply of DC current to the motors552A and 552B. Further, the boost switch may be provided in combinationwith the hybrid controller or separately as previously described asvarious combinations of these individual elements may be selected.

In an embodiment, the dual blade DC motor combination may provide a 21inch path for cutting vegetation wherein similar rotational speeds of16,000 to 19,000 feet per minute blade speed may be experienced eitheron battery or on the AC line voltage with the higher rotational speedindicated when operating using line voltage. Such rotational speedindicates a potential of 5,800 to 6,900 RPM. These speeds typify theefficiency of the motor when the mower 10 is implemented in anon-cutting environment. During cutting of vegetation, the rotationalspeed of the blade tip may be 12,000 to 18,000 feet per minute, againwith the higher rotational speeds indicated when operating on linevoltage. These speeds relate to approximately 4,300 to 6,500 RPM on eachof the two blades providing a 19 inch cutting diameter. Similar motorsmay be provided as previously described for implementation by theelectric lawnmower of the present invention.

Further, the horsepower at cutting speed may be anywhere from 1.5 to 2.0HP with the battery capacity being approximately 480 watt hours asnecessary. Excellent cutting at these speeds with either the singlemotor or dual motor implementation may be experienced with adequateblade speed, cutting action and suction experienced within the lawnmowerdeck or housing. Mulching may also be accomplished when operating atthese speeds and may be increased by implementation of the boost featurepreviously described which would be available to both DC electric motorsduring operation if implemented in one of the many various boost andconserver implementations previously described. Referencing again FIG.30, both motors are depicted in parallel combination with the motorsseeing approximately 60 volts from the power supply. When the motors arein such parallel connectivity, as one motor is loaded disproportionatelydue to various factors from either air resistance or vegetation andcutting resistance, the second motor slows down due to the reduced poweravailable from the battery caused by the internal resistance and thehigher amperage of the power supply as is depicted. Such self adjustmentof the motor and hence blade speeds provide automated self regulation ofboth motors.

Given the power supply and control embodiment depicted in FIG. 31, theuser may select either AC or DC operation, which also serves as acircuit setting switch, and places the two motors 552 a and 552 b ineither series or parallel configuration. When in DC mode, the battery 52supplies constant current and may result in better performance of themotors. Further, when placed in DC mode, the motors are in parallel and,as one motor is loaded disproportionately, the second motor may slowdown due to the reduced power available from the battery pack caused bythe internal resistance of the power supply design and motorconfiguration and by the higher amperage.

Turning to the alternative construction and embodiment of the powersupply and control circuitry of FIG. 31, the power supply and controlcircuit 560 indicates that the dual DC motors 552A and 552B areconnected to the output of the AC/DC power selection switch 521 whichtoggles the power supply of the circuit from the full bridge rectifier501 when in the AC position, to the DC battery source 52 when in the DCposition as is depicted. The output of the power selection switch 521feeds the voltage meter shown which is connected in parallel with thedouble pole, double throw interlock handle switch 31. The interlockhandle switch 31 toggles between short in the DC motors 552A and 552Bthrough a resistor, R1 to ground and connecting the output of the powerselection switch 521, a three pole double throw switch in this disclosedembodiment, through circuit breaker 28 to the dual DC motors 552A and552B. When the power selection switch 521 is in the AC selectionposition, the dual motors M1 and M2 are connected in series therebysplitting the voltage output of the rectifier. In such operation, thefull bridge rectifier may provide 120 VDC with 60 V the seen by eachmotor. When the AC/DC power selection switch 521 is in the DC position,the motors M1 and M2 are connected in parallel thereby each sharing inthe DC voltage output of the battery pack. The battery, being a constantcurrent power supply, may provide better performance of the DC motors M1and M2 in parallel and thus the connection as is described may beprovided with the capability of switching between parallel and seriesconnectivity of the motors M1 and M2 depending on the power source.

Further, as disclosed in FIG. 31, a full bridge rectifier or possiblyother current rectification is depicted wherein the 120 VAC is inputinto the hybrid controller (not depicted as previously shown forsimplicity). The full bridge rectifier in this embodiment may readily bereplaced by various rectification circuitry, such as that previouslydisclosed herein. Thus, the rectifier depicted may be replaced by othercurrent rectification means to rectify the current from AC to DC. Theseknown systems include but are not limited to pulse width modulationwhich may readily be implemented herein.

When AC mode is selected from the user selectable power selection switchshown in FIG. 31, the total current going through many of the switchesand electronic circuit elements presented herein may be one half of thatgoing through the same switches and electronic circuit elements in theparallel or battery mode, given the embodiments depicted as a result ofthe rectification of the current and positioning of the loads. In otherwords, as shown in FIG. 31, the battery pack provides 60 VDC which isshared by the dual motors in parallel and the AC input line provides 120VDC to be split by the dual motors in series in the disclosedembodiments. The response to uneven loading also may be more desirableas previously described in parallel as opposed to in series mode, since,when in series mode, as one motor is disproportionately loaded and slowsdown, the other motor will speed up. The actual speed modification ofthe motors in series however may be mitigated due to the nature of theair resistance to the blades and the significant amount of energy andload required to move the air in the mower housing. The relationshipbetween air movement resistance and blade speed is an exponentialrelationship thus adding a significantly higher load when the blade isspinning faster, thus tending to cause the blades to operate at similarspeeds in these embodiments. However, either combination of eitherseries or parallel connection of the two DC motors as is depicted mayreadily be implemented and such description as set forth herein is notdeemed limiting.

In both configurations of the dual motor design depicted, the abilityand functionality of the boost and conserve features are still presentin that the blade speed for both motors may be reduced in a conservemode, particularly when operating off of the DC battery power supply inorder to increase charge life. As shown in FIG. 30, a boost and conserveswitch and feature may be implemented in conjunction with the hybridcontroller shown. However, many differing combinations of the boost andconserve feature previously described may be applicable to either designand power supply shown. In conjunction with the power supply and controldepicted in either embodiment, a secondary battery pack may be utilizedas discussed herein to increase the voltage output of the DC operationand power supply thereby increasing the blade speed for both motorswhile also allowing battery use to be conserved in a second statethereby increasing overall run life per charge. Alternatively, increasedvoltage may be provided directly from the hybrid controller as depictedwhen drawing power from AC power supply.

In addition to the dual motor or other designs depicted, a dual voltagemotor may also be desirable. Such dual voltage may be seen by theelectric motor when switching between rectified line voltage from anoutlet or from a battery pack, which may, in one embodiment, roughly beone half the line voltage. It would be preferable that a dual voltageelectric motor be implemented for hybrid operation wherein allelectrical or electro-mechanical aspects of the electric motor are inoperation and use when utilizing either high voltage operation or lowervoltage operation. By all electrical or electro-mechanical aspects beingin use, it is meant that windings, brushes, commutators and otheraspects of the electrical motor are mostly in operation and electricallyconnected to the power supply, whether high voltage AC or lower voltageDC. The described DC voltage permanent magnet motor design of theexemplary embodiment allows a single motor to operate using twodifferent DC voltages. This may be accomplished through providing ahybrid controller which places electrically separated windings on thearmature in either serial or parallel configuration, parallel for lowervoltage operation and serial configuration for higher voltageconfiguration. In either configuration, the voltage potential acrosseach coil will be about 60 VDC, or half the high voltage, as the coilsare placed in series when in AC mode and in parallel when in lowervoltage mode. Similarly alternative constructions may be implemented inthe embodiment shown.

Presently, in the various embodiments depicted, a dedicated electricmotor design may be implemented in the hybrid electric lawnmower whichimplements the ability and functionality of direct AC power suppliedfrom a standard line voltage power source providing 120 VAC, or, ofpower provided from a secondary power supply source such as a batterypack, which would supply about 60 VDC to about 72 VDC, as is necessaryor as is designed, all to the same electric motor driving the blade onthe mower housing. In one embodiment, the hybrid controller utilized inthe embodiment may convert the 120 VAC to 120 VDC through the use ofvarious techniques, such as a rectifier or other circuitimplementations. In such implementation, the user would elect to switchthe mower power supply selection switch to AC, the hybrid controllerwould rectify the voltage to DC and the motor would operate at apossibly higher voltage supply. Alternatively, user selection of thepower selection switch to DC would electrically connect the battery packor other lower voltage power supply to the motor in order to operate theblade on the mower housing.

In either situation, user selection of AC operation as when the mowerembodiment depicted is plugged into an outlet, or when user selectionhas been modified to DC operation for running the mower off of thebattery pack or other direct current power supply, the electric mower ofthe present embodiment may alternate between high voltage operation orlow voltage operation, the low voltage supply typically being one halfthe high voltage supply. Through implementation of dual core windingswhich are electrically separated and both rated at the lower voltagelevel, the rpm of the hybrid motor presently described may be maintainedin either voltage configurations.

Referring now to FIG. 32, there is shown a dual voltage motor 800. Inthis exemplary embodiment, the dual voltage motor 800 includes apermanent magnet 816 and a single armature 808 connected to an axle 818.Attached to the armature 808 are a first commutator 802 separated from asecond commutator 804. The first commutator 802 connects to a first setof windings (coils) 810, and the second commutator 804 connects to asecond set of windings 812. The first set of windings 810 is separatedfrom the second set of windings 812. Further, the first commutator 802is in electric contact with a corresponding first set of brushes 806Aand 806B, and the second commutator 804 is in electric contact with acorresponding second set of brushes 814A and 814B. The two sets ofbrushes (806 and 814) may be selectively configured through the use of auser selection switch which reconfigures the windings (810 and 812) onthe motor from series connectivity (for higher voltage source such asrectified line voltage), to parallel connectivity (for a lower voltagesource such as a battery pack). If the higher voltage is approximatelytwice the potential of the lower voltage, the power supply will provideapproximately the same voltage potential across a first and a secondcommutator on the electric motor.

Referring now to FIG. 33, there is shown a parallel configuration of thedual voltage motor. In such configuration, the positive terminal of theV1 voltage source is connected to the terminal T1 of the motor, and thenegative terminal of the V1 voltage source is connected to the terminalT2 of the motor. Terminals T1 and T2 are connected to the firstcommutator 802 through brushes 806A and 806B, which creates a voltagepotential of V1 across the first coil 810. The positive terminal of theV1 voltage source is also connected to terminal T3 of the motor, and thenegative terminal of the V1 voltage source is also connected to terminalT4 of the motor. The terminals T3 and T4 are connected to the secondcommutator 804 through brushes 814A and 814B, which creates a voltagepotential of V1 across the second coil 810.

Referring to FIG. 34, there is shown a series configuration of the dualvoltage motor. In such configuration, the positive terminal of the V2voltage source is connected to the terminal T1 of the motor, and thenegative terminal of the V2 voltage source is connected to the terminalT4 of the motor. Further, terminal T2 is connected in series to terminalT3. Terminals T1 and T2 are connected to the first commutator 802through brushes 806A and 806B, and terminals T3 and T4 are connected tothe second commutator 804 through the brushes 814A and 814B. Thisconfiguration creates a voltage potential of V2 across both coils whichmeans that each coil will have a potential of a half of V2 in thepresent embodiment.

FIG. 35 depicts an exemplary circuit implementation of an electric mowerutilizing a dual voltage motor 553. The coils may be placed in either ahigh voltage configuration or a low voltage configuration by the user.In a high voltage configuration the coils 554A and 554B are placed inseries. In a low voltage configuration the coils are placed in parallel.User selection of the high or low voltage configuration may be achievedthrough the use of the three pole double throw switch SW1 which providesthe operator of the hybrid mower presently described in this embodimentthe ability to provide a power supply of 120 VAC for higher voltageoperation or 60-72 VDC for lower voltage operation.

In one specific embodiment, for example, when the mower is connected toa standard AC power source of 120 VAC, a rectifier may rectify thevoltage to about 120 VDC (a higher voltage source). Thus, a seriesconfiguration will provide each set of coils about 60 VDC.Alternatively, when the mower is connected to a 60 VDC battery pack (alower voltage source), a parallel configuration will provide each set ofcoils about 60 VDC as well. Substantially the same voltage provided tothe sets of coils in both higher and lower voltages results insubstantially the same revolutions per minute/rounds-per-minute (RPM) ofthe motor. In this manner, the dual-voltage lawnmower may be capable ofexecuting speed control over the motor and the cutting blade withoututilizing an electronic controller. This may represent a significantcost benefit to a consumer. In one specific embodiment, the lack of acontroller may represent a cost savings of approximately ten percent. Itwill be appreciated that the number of windings in the motor may varyand/or the diameter of wires including the windings may vary.

It will be appreciated that while the hybrid device disclosed herein hasbeen described with some specificity as a hybrid lawnmower, many otherdevices may be provided which also utilize some or all of the featuresdisclosed herein. Moreover, while the hybrid lawnmower described abovehas been shown and described as including a cutting component housingincluding a cutting blade, it will be appreciated that the cutting bladeis exemplary only, and a variety of other working elements may beutilized with the hybrid electric device of the present invention. Forexample, FIG. 41 illustrates a hybrid snow blower 10. The hybrid snowblower may include a cutting component housing including at least oneimpeller/fan (blowing component). In exemplary embodiments, the hybridsnow blower 10 may implement a removable battery/battery assembly whichmay be removed after each use of the snow blower 10 and stored indoorsfor preserving the battery during winter conditions. It is contemplatedthat other hybrid powered devices may be provided as well, includinglarge devices similar to the mower and the snow blower (e.g.,chipper/shredders, reel mowers, tillers, thatchers, and/or aerators), aswell as small devices, such as handheld devices like trimmers and/oredgers. Moreover, it will be appreciated that these devices may includea variety of working elements. Further, these working elements may beprovided in various quantities. For example, one hybrid electric devicemay include two working elements (and various types and combinations ofmotors for driving the working elements as needed), while another hybriddevice may include three working elements (with an appropriate numberand configuration of motors as needed).

It is believed that the present invention and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, constructionand arrangement of the components thereof without departing from thescope and spirit of the invention or without sacrificing all of itsmaterial advantages. The form herein before described being merely anexplanatory embodiment thereof, it is the intention of the followingclaims to encompass and include such changes.

1. A device, comprising: a housing configured with a working element; amotor configured for urging motion of the working element; a powercontrol module, the power control module configurable for being inelectrical connection with at least one of the motor, a first powersource configuration and a second power source configuration, the firstpower source configuration configurable for being electrically connectedto a battery assembly having a Direct Current (DC) power output, thesecond power source configuration configurable for being electricallyconnected to a power inverter, the power inverter configured forreceiving an Alternating Current (AC) power and further configured foroutputting a DC power to the second power source configuration, whereinthe motor receives power via the power control module from at least oneof the first power source configuration and the second power sourceconfiguration.
 2. The device as claimed in claim 1, wherein the deviceis an electric lawnmower.
 3. The device as claimed in claim 1, whereinthe power control module is manually operable via a power selectionswitch for selecting between the first power source configuration andthe second power source configuration.
 4. The device as claimed in claim3, wherein the power control module includes an automatic powerselection configuration for automatically selecting the second powersource configuration when the second power source configuration receivesDC power from the power inverter.
 5. The device as claimed in claim 4,wherein the automatic power selection configuration is overridable bymanual selection via the manually operable power selection switch. 6.The device as claimed in claim 1, wherein the power control modulefurther includes a both configuration, wherein when the bothconfiguration is selected, the motor receives power from both the firstpower source configuration and the second power source configuration. 7.The device as claimed in claim 1, wherein the power inverter is arectifier and filter combination.
 8. The device as claimed in claim 1,wherein the power inverter includes a step down controller.
 9. Thedevice as claimed in claim 8, wherein the step down controller includesa voltage rectifier and a pulse width modulator.
 10. The device asclaimed in claim 1, wherein the battery assembly has a normal outputvoltage of 60 volts.
 11. The device as claimed in claim 1, wherein thepower inverter receives an AC input of 120 volts, and outputs a DCoutput of 60 volts.
 12. The device as claimed in claim 1, wherein thebattery assembly includes a stack of DC batteries connected in series.13. The device as claimed in claim 1, wherein the battery assembly isremovable from the device, and is chargeable at a location separate fromthe device.
 14. The device as claimed in claim 1, wherein the batteryassembly is chargeable while on board the device and during theoperation of the device.
 15. The device as claimed in claim 3, whereinthe power selection switch is positioned on the housing.
 16. The deviceas claimed in claim 3, wherein the power selection switch is positionedon a handle of the device.
 17. A device, comprising: a housingconfigured with a working element; a motor configured for urging motionof the working element; a power control module, the power control moduleconfigurable for being in electrical connection with at least one of themotor, a first power source configuration and a second power sourceconfiguration, the first power source configuration configurable forbeing electrically connected to a battery assembly having a DC poweroutput, the second power source configuration configurable for beingelectrically connected to a power inverter, the power inverterconfigured for receiving an AC power and further configured foroutputting a DC power to the second power source configuration, whereinthe motor receives power via the power control module from at least oneof the first power source configuration and the second power sourceconfiguration, wherein the power control module further includes a boostconserve switch including a conserve mode for supplying a first voltageto the motor when the boost conserve switch is established in theconserve mode and a boost mode for supplying a second voltage to themotor when the boost conserve switch is established in the boost mode,the first voltage being less than the second voltage.
 18. The device asclaimed in claim 17, wherein the power control module is configured forcontrolling motor speed by supplying at least one of the first voltageand the second voltage when the boost conserve switch is established inat least one of the conserve mode and the boost mode.
 19. The device asclaimed in claim 17, wherein motor speed when the first voltage issupplied is below 14,000 feet per minute blade speed, and motor speedwhen the second voltage is supplied is above 15,000 feet per minuteblade speed.
 20. The device as claimed in claim 17, wherein the boostconserve switch is configured for at least one of establishing anelectrical connection with an auxiliary battery and terminating anelectrical connection with an auxiliary battery.
 21. The device asclaimed in claim 17, wherein the boost conserve switch is configured forat least one of increasing DC power output of the power inverter anddecreasing DC power output of the power inverter.
 22. The device asclaimed in claim 17 wherein the boost conserve switch is configurablefor at least one of establishing an electrical connection with thebattery assembly and terminating an electrical connection with thebattery assembly.
 23. A device, comprising: a housing configured with afirst working element and a second working element; a first motorconfigured for urging motion of the first working element; a secondmotor configured for urging motion of the second working element; apower control module configurable for being in electrical connectionwith at least one of the first motor, the second motor, a first powersource configuration and second power source configuration, the firstpower source configuration configurable for being electrically connectedto a battery assembly having a DC power output, the second power sourceconfiguration configurable for being electrically connected to a powerinverter, the power inverter configured for receiving an AC power andfurther configured for outputting a DC power to the second power sourceconfiguration, wherein the first motor and the second motor areconfigured for receiving power via the power control module from atleast one of the first power source configuration and the second powersource configuration.
 24. The device as claimed in claim 23, wherein thefirst and the second motors are electrically connected in a parallelconfiguration.
 25. The device as claimed in claim 23, wherein the firstand the second motors are electrically connected in a seriesconfiguration.
 26. The device as claimed in claim 23, wherein the powercontrol module further includes a circuit setting switch having a firstcircuit setting and a second circuit setting, the circuit setting switchallowing the first motor and the second motor to be electricallyconnected in a parallel configuration when the circuit setting switch isestablished at the first circuit setting, the circuit setting switchfurther allowing the first motor and the second motor to be electricallyconnected in a series configuration when the circuit setting switch isestablished at the second circuit setting.
 27. The device as claimed inclaim 26, wherein the circuit setting switch is a three pole doublethrow switch configured for electrically connecting with at least one ofthe first power source configuration, the second power sourceconfiguration, the first motor and the second motor, the circuit settingswitch being further configured for automatically selecting the firstcircuit setting when the circuit setting switch is connected to thefirst power source configuration, the circuit setting switch beingfurther configured for automatically selecting the second circuitsetting when the circuit setting switch is connected to the second powersource configuration.
 28. The device as claimed in claim 23, wherein thepower control module further includes a boost conserve switch includinga conserve mode for supplying a first voltage to the first motor and thesecond motor when the boost conserve switch is established in theconserve mode and a boost mode for supplying a second voltage to thefirst motor and the second motor when the boost conserve switch isestablished in the boost mode, the first voltage being less than thesecond voltage.
 29. A device, comprising: a housing configured with aworking element; a motor configured for urging motion of the workingelement; a power control module, the power control module configurablefor being in electrical connection with at least one of the motor, afirst power source configuration and a second power sourceconfiguration, the first power source configuration configurable forbeing electrically connected to a battery assembly having a DirectCurrent (DC) power output, the second power source configurationconfigurable for being electrically connected to a power inverter, thepower inverter configured for receiving an Alternating Current (AC)power and further configured for outputting a DC power to the secondpower source configuration; and a switch for selecting between a firstmode for charging the battery assembly when the power control module isreceiving AC power and a second mode for not charging the battery,wherein the motor receives power via the power control module from atleast one of the first power source configuration and the second powersource configuration.
 30. A device, comprising: a housing configuredwith a working element; a motor configured for urging motion of theworking element; the motor mounted on a deck having a first rigidity;and a reinforcing framework having a second rigidity mounted to thedeck.
 31. The device as claimed in claim 30, wherein the deck comprisesat least one of plastic and fiberglass.
 32. The device as claimed inclaim 31, wherein the deck comprises reinforcing ribs.
 33. The device asclaimed in claim 30, wherein the reinforcing framework comprises steel.34. The device as claimed in claim 33, wherein the reinforcing frameworkcomprises a substantially tubular shape.
 35. The device as claimed inclaim 30, further comprising: a handle; and at least one axle towerpositioned on the deck, wherein the handle is in supportive contact withthe axle towers.
 36. The device as claimed in claim 35, furthercomprising: a controller mounted on the deck in electric connection withthe motor, wherein the motor, the controller, the axle towers and thedeck form a box structure.